1. Field of the Invention
This invention relates to fastening devices and especially to pin connections.
In particular, this invention concerns a coupling pin connection for securing a watchband to a watchcase.
2. Description of Related Art
A watch typically includes a watchcase provided with a set of spaced apart projecting horns or lugs at a top and a bottom of the watchcase and a watchband that is attached to the lugs. Each set of lugs is bridged by a watchband cross-bar having a retractable spring-biased pin extending axially from the cross-bar. The respective ends of the pin are adapted to be received within a cavity formed in each of the lugs. The respective ends of the watchband are provided with a transverse bore to accommodate the cross-bar whereby the watchband can be linked to the lugs. The spacing of the cavity with respect to the watchcase is such that there is a clearance between the end of the watchband and the watchcase. In order to replace the watchband, the pins must be displaced inwardly with a suitable tool to release the cross-bar from the lugs after which the watchband can be decoupled from the watchcase.
Alternatively, the watchcase to watchband attachment may be provided by a threaded cross-bar.
A disadvantage of the previously described coupling arrangements is that, in many instances, the coupling procedure must be performed by a jeweler or skilled person having the necessary tools.
Another problem with the above-mentioned spring-biased coupling arrangements is that if a sufficient force is exerted upon the watchband, the cross-bar can snap or be deformed and the watchband can become detached from the watchcase.
A further shortcoming of the disclosed coupling arrangements is that they are not adapted for watch designs wherein the watchcase and the watchband are integral for aesthetic purposes and do not have a clearance between the watchcase and the watchband.
Yet another limitation of the above-noted coupling arrangements is that they do not provide for the quick release of the watchband for use with watches having interchangeable watchbands.
Several watchband coupling arrangements have attempted to overcome the above-noted deficiencies. For example, U.S. Pat. No. 5,951,193 discloses a mechanism for connecting a watchband without using a spring-pin. A stepped pin cooperates with a cocoon-shaped ring by pulling the watch casing and band longitudinally to connect the watchband. This arrangement however, does not provide the dependability and ease of use of the present invention.
The watchband coupling connection illustrated in U.S. Pat. No. 5,914,913 relies upon the interaction of a central bar having an opening and attachment lugs having cooperating pin shafts however, the pin shafts have tips that can be susceptible to failure. Furthermore, this connection does not encompass contiguous contact between the watchcase and the watchband.
U.S. Pat. No. 7,451,528 describes a watchband connection to a watchcase using a pin that is moveable into different positions relative to the band, however, this arrangement is not adaptable for facilitating removal of the pin or for compatible use with interchangeable watchbands.
The coupling assembly for a watchband as disclosed in U.S. Pat. No. 8,007,165 utilizes a threadably engageable screwbar. The coupling and decoupling requires a special tool for tightened and/or removal of the screwbar and therefore it is not as convenient to use as is the easily releasable coupling pin connection of this invention that does not require any special tools.